“We believe, with the others who have signed this Pledge, that we are truly on the cusp of life-changing achievements that will improve our collective quality of life, and have an everlasting impact on generations to come,” said Groupon founder Eric Lefkofsky and his wife in their letter signaling their intention to give at least half their wealth to charitable causes. Before the Lefkofskys signed the Giving Pledge this holiday season however, there were already indications that they were ramping up their giving.

For one, there’s the fancy new website they launched a couple years ago to highlight the areas they support, and help potential grantees navigate the grant application process. Secondly, their tax filings for the past several years show a major increase in the both the assets and charitable contributions of the Lefkofsky Family Foundation. In 2010, they gave out $1.9 million in grants, and were holding $4.6 million in assets. Just two years later, they gave out $4.6 million in grants, and are now holding $18 million in assets.

They’ve also been stepping up on their larger donations, which are sometimes done outside their foundation. In the last several years, they’ve given $7 million to the Steppenwolf Theatre Co., and $6 million to the Ann and Robert H. Lurie Children's Hospital, the two organizations topping the list of their charitable giving.

“Our desire to give has always been there, but our ability to give has changed dramatically over time,” says Lefkofsky. The commitment, he says, was easy to make, since he and his family have more than they could ever use or need, making their giving relatively painless. Their inspiration, at least in part, he says, has been those who cannot afford to give much, yet still find a way to be generous in their giving. His wife lost her sister to cancer when she was five years old, which he says weighs a profound influence on their philanthropy.

The Lefkofsky Family Foundation focuses on four key areas of giving: medical research, arts and culture, education, and human rights. In some of these areas, they have a clear philanthropic direction. In others, they still seem to be searching for traction. With a net worth of $1.7 billion, they have a long way to go to fulfill their pledge, but they’re also young— just in their early 40’s— so they should have plenty of time to figure out how to get the most impact from their giving.

Check out Eric's full profile on Inside Philanthropy, and learn more about the causes the Lefkofskys support.